A REPORT EDUCATIONAL TOUR TO

HYDRO ELECTRIC POWER STATIONSSubmitted to

Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad

In Partial Fulfilment of Requirements

For the award of Degree of

BACHELOR OF TECHNOLOGY

IN

MECHANICAL ENGINEERING

By

SUDEEP MISHRA (07K31A0347)

DEPARTMENT OF MECHANICAL ENGINEERING

ROYAL INSTITUTE OF TECHNOLOGY & SCIENCE(Affiliated to Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad)

Damergidda(V),Chevella (M), R.R. Dist, Andhra Pradesh

2010-2011

HISTORY OF HYDROPOWER

Humans have been harnessing water to perform work for thousands of

years. The Greeks used water wheels for grinding wheat into flour more than

2,000 years ago. Besides grinding flour, the power of the water was used to

saw wood and power textile mills and manufacturing plants.

For more than a century, the technology for using falling water to

create hydroelectricity has existed. The evolution of the modern hydropower

turbine began in the mid-1700s when a French hydraulic and military

engineer, Bernard Forest de Bélidor wrote Architecture Hydraulique. In this

four volume work, he described using a vertical-axis versus a horizontal-axis

machine.

During the 1700s and 1800s, water turbine development continued. In

1880, a brush arc light dynamo driven by a water turbine was used to

provide theatre and storefront lighting in Grand Rapids, Michigan; and in

1881, a brush dynamo connected to a turbine in a flour mill provided street

lighting at Niagara Falls, New York. These two projects used direct-current

technology.

Alternating current is used today. That breakthrough came when the

electric generator was coupled to the turbine, which resulted in the world's,

and the United States', first hydroelectric plant located in Appleton,

Wisconsin, in 1882.

HYDROELECTRIC POWER / HYDROELECTRICITY

Hydro means "water". So, hydropower is "water power" and

hydroelectric power is electricity generated using water power. Potential

energy (or the "stored" energy in a reservoir) becomes kinetic (or moving

energy). This is changed to mechanical energy in a power plant, which is

then turned into electrical energy. Hydroelectric power is a renewable

resource.

In an impoundment facility (see below), water is stored behind a dam

in a reservoir. In the dam is a water intake. This is a narrow opening to a

tunnel called a penstock.

Water pressure (from the weight of the water and gravity) forces the

water through the penstock and onto the blades of a turbine. A turbine is

similar to the blades of a child's pinwheel. But instead of breath making the

pinwheel turn, the moving water pushes the blades and turns the turbine.

The turbine spins because of the force of the water. The turbine is connected

to an electrical generator inside the powerhouse. The generator produces

electricity that travels over long-distance power lines to homes and

businesses. The entire process is called hydroelectricity.

TYPES OF HYDROPOWER PLANTS

There are three types of hydropower facilities: impoundment,

diversion, and pumped storage. Some hydropower plants use dams and

some do not. The images below show both types of hydropower plants.

Many dams were built for other purposes and hydropower was added

later. In the United States, there are about 80,000 dams of which only 2,400

produce power. The other dams are for recreation, stock/farm ponds, flood

control, water supply, and irrigation. Hydropower plants range in size from

small systems for a home or village to large projects producing electricity for

utilities.

IMPOUNDMENT

The most common type of hydroelectric power plant is an

impoundment facility. An impoundment facility, typically a large hydropower

system, uses a dam to store river water in a reservoir. Water released from

the reservoir flows through a turbine, spinning it, which in turn activates a

generator to produce electricity. The water may be released either to meet

changing electricity needs or to maintain a constant reservoir level.

DIVERSION

A diversion, sometimes called run-of-river, facility channels a portion of a

river through a canal or penstock. It may not require the use of a dam.

PUMPED STORAGE

When the demand for electricity is low, a pumped storage facility

stores energy by pumping water from a lower reservoir to an upper

reservoir. During periods of high electrical demand, the water is released

back to the lower reservoir to generate electricity.

Pumped storage hydro-electricity works on a very simple principle.Two

reservoirs at different altitudes are required. When the water is released,

from the upper reservoir, energy is created by the downflow which is

directed through high-pressure shafts, linked to turbines.

In turn, the turbines power the generators to create electricity.Water is

pumped back to the upper reservoir by linking a pump shaft to the turbine

shaft, using a motor to drive the pump.

The pump motors are powered by electricity from the National Grid -

the process usually takes place overnight when national electricity demand

is at its lowestA dynamic response - Dinorwig's six generating units can

achieve maximum output, from zero, within 16 seconds.Pump storage

generation offers a critical back-up facility during periods of excessive

demand on the national grid system.

.

SIZES OF HYDROELECTRIC POWER PLANTS

Facilities range in size from large power plants that supply many

consumers with electricity to small and micro plants that individuals operate

for their own energy needs or to sell power to utilities.

Large hydropower

Although definitions vary, the U.S. Department of Energy defines large

hydropower as facilities that have a capacity of more than 30 megawatts.

Small hydropower

Although definitions vary, DOE defines small hydropower as facilities

that have a capacity of 100 kilowatts to 30 megawatts.

Microhydropower

A microhydropower plant has a capacity of up to 100 kilowatts. A small

or microhydroelectric power system can produce enough electricity for a

home, farm, ranch, or village.

TURBINES INSTALLATION

LAYOUT OF HYDROELECTRIC POWER PLANTS

Hydroelectric power plants convert the hydraulic potential energy from

water into electrical energy. Such  plants are suitable were water with

suitable head are available. The layout covered in this article is just a simple

one and only cover the important parts of  hydroelectric plant.The different

parts of  a hydroelectric power plant are

(1) Dam

Dams are structures built over rivers to stop the water flow and form a

reservoir.The reservoir stores the water flowing down the river. This water is

diverted to turbines in power stations. The dams collect water during the

rainy season and stores it, thus allowing for a steady flow through the

turbines throughout the year. Dams are also used for controlling floods and

irrigation. The dams should be water-tight and should be able to withstand

the pressure exerted by the water on it. There are different types of dams

such as arch dams, gravity dams and buttress dams. The height of water in

the dam is called head race.

(2) Spillway

A spillway as the name suggests could be called as a way for spilling of

water from dams. It is  used to provide for the release of flood water from a

dam. It is used to prevent over toping of the dams which could result in

damage or failure of  dams. Spillways could be controlled type or

uncontrolled type. The uncontrolled types start releasing water upon water

rising above a particular level. But in case of the controlled type, regulation

of flow is possible.

(3) Penstock and Tunnel

Penstocks are pipes which carry water from the reservoir to the

turbines inside power station. They are usually made of  steel and are

equipped with gate systems.Water under high pressure flows through the

penstock. A tunnel serves the same purpose as a penstock. It is used when

an obstruction is present between the dam and power station such as a

mountain.

(4) Surge Tank

Surge tanks are tanks connected to the water conductor system. It

serves the purpose of reducing water hammering in pipes which can cause

damage to pipes. The sudden surges of water in penstock is taken by the

surge tank, and when the water requirements increase, it supplies the

collected water thereby regulating water flow and pressure inside the

penstock.

(5) Power Station

Power station contains a turbine coupled to a generator. The water

brought to the power station rotates the vanes of the turbine producing 

torque and rotation of turbine shaft. This rotational torque is transfered to

the generator and is converted into electricity. The used water is released

through the tail race. The difference between head race and tail race is

called gross head and by subtracting the frictional losses we get the net

head available to the turbine for generation of electricity.

NATIONAL HYDROELECTRIC POWER CORPORATION

NHPC Limited (Formerly National Hydroelectric Power

Corporation), A Govt. of India Enterprise, was incorporated in the year 1975

with an authorised capital of Rs. 2000 million and with an objective to plan,

promote and organize an integrated and efficient development of

hydroelectric power in all aspects. Later on NHPC expanded its objects to

include other sources of energy like Geothermal, Tidal, Wind etc.

Market Value

At present, NHPC is a schedule 'A' Enterprise of the Govt. of India with

an authorized share capital of Rs. 1,50,000 Million . With an investment base

of over Rs. 2,20,000 million Approx. In 2009-2010 NHPC made a profit after

tax of Rs2090 crores . A increase of 94% than the previous year profit of

1050 crores. NHPC is among the top ten companies in India in terms of

investment. Department of Public Enterprise, Govt. of India recently

conferred prestigious Miniratna status to NHPC.

Initially, on incorporation, NHPC took over the execution of Salal Stage-

I, Bairasiul and Loktak Hydro-electric Projects from Central Hydroelectric

Projects Control Board. Since then, it has executed 13 projects with an

installed capacity of 5175 MW on ownership basis including projects taken up

in joint venture. NHPC has also executed 5 projects with an installed capacity

of 89.35 MW on turnkey basis. Two of these projects have been

commissioned in neighbouring countries i.e. Nepal and Bhutan.

On-going Work

Presently NHPC is engaged in the construction of 11 projects

aggregating to a total installed capacity of 4622 MW . NHPC has planned to

add 5322 MW during 11th Plan period. 10 projects of 9981 MW are awaiting

clearances/Govt. approval for their implementation. Detailed Projects report

or Feasibility Report are being prepared for 7 projects of 5755 MW.

Since its inception in 1975, NHPC has grown to become one of the

largest organizations in the field of hydro power development in the country.

With its present capabilities, NHPC can undertake all activities from concept

to commissioning of hydroelectric projects.

This is a list of major hydroelectric power plants in India.

STATIOM COMMUNITY OPERATORGENERATOR

UNITSCAPACITY (MW)

Srisailam Dam Andhra Pradesh APGenco 6 × 150, 7 × 110 1,670

Nagarjunasagar Andhra Pradesh APGenco1 X 110, 7 X 100.8,

5 X 30965

Sardar Sarovar Gujarat SSNNL 6X200, 5X140 1,450Baspa-II Himachal Pradesh JHPL 3 X 100 300

Nathpa Jhakri Himachal Pradesh SJVNL 6 X 250 1,500Bhakra Dam Punjab BBMB 5 X 108, 5 X 157 1,325

Dehar Himachal Pradesh BBMB 6 X 165 990Baira Suil Himachal Pradesh NHPC 3 X 60 180Chamera-I Himachal Pradesh NHPC 3 X 180 540Chamera-II Himachal Pradesh NHPC 3 X 100 300

Pong Himachal Pradesh BBMB 6 x 66 396Uri Hydroelectric

DamJammu & Kashmir NHPC 4 X 120 480

Dulhasti Jammu & Kashmir NHPC 3 X 130 390Salal Jammu & Kashmir NHPC 6 X 115 690

Sardar Sarovar[5] 400

Sharavathi Karnataka KPCL10 X 103.5, 2X27.5,

4 X 601,469

Kalinadi Karnataka KPCL 2X50, 2x135, 4X150, 3X50, 3X40

1,225

Linganamakki Dam Karnataka 55Idukki Kerala KSEB 6 X 130 780

Bansagar Dam Madhya Pradesh 425Bargi Dam Madhya Pradesh 105

Madikheda Dam Madhya Pradesh 60Omkareshwar Madhya Pradesh NHPC 8 X 65 520Indira Sagar Madhya Pradesh NHPC 8 X 125 1,000

Loktak Manipur NHPC 3 X 35 105Khuga Dam Manipur

Koyna Maharashtra MahaGenco 18 X 106.67 1,920Mulshi Dam Maharashtra 150

Jayakwadi Dam Maharashtra 12Kolkewadi Dam Maharashtra

Rangeet Sikkim NHPC 3 X 20 60Teesta-V Sikkim NHPC 3 X 170 510Tanakpur Uttarakhand NHPC 3 X 40 120

Dhauliganga-I Uttarakhand NHPC 4 X 70 280Loharinag Uttarakhand NTPC 4 X 150 600

THE FOLLOWING HYDRO ELECTRIC POWER PLANTS WERE VISITED

DURING THE EDUCATIONAL TOUR .

1. NAGARJUNA SAGAR DAM – ON 29TH NOVEMBER, 2010

2. SRISAILAM HYDRO POWER PLANT – ON 30TH NOVEMBER, 2010

1. NAGARJUNA SAGAR DAM

FACTS AND FIGURES

Official name Nagarjuna Sagar Dam

LocationNalgonda District, Andhra

Pradesh, India

Coordinates 16°36′N 79°20′E / 16.6°N 79.333°E

Construction bega

n1956

Opening date 1960

Construction cost 1300 crore rupees

DAM AND SPILLWAYS

Length 1,450 metres (4,757 ft)

Height 124 metres (407 ft) from river level

Impounds Krishna River

RESERVOIR

Creates Nagarjuna Sagar Reservoir

Capacity 11,472 million cubic metres

Catchment area 215000 km² (83012 sq mi)

Nagarjuna Sagar Dam is the world's largest masonry dam built

across Krishna River in Nagarjuna Sagar,Nalgonda District of Andhra

Pradesh, India. It is downstream to the Nagarjuna Sagar reservoir with a

capacity of up to 11,472 million cubic metres which is the world's largest

man-made lake with a concrete wall of that measures 6 ft (1.8 m). thick. The

dam is 490 ft (150 m). tall and 16 km long with 26 gates which are 42 ft (13

m). wide and 45 ft (14 m). tall.It is one of the earliest irrigation and hydro-

electric projects in India. The dam provides irrigation water to the Nalgonda

District, Prakasam District, Khammam District and Guntur District.

HISTORY

The proposal to construct a dam to use the excess waters of the

Krishna river was put forward by the British rulers in 1903. Siddeswaram,

Hyderabad and Pulichintala were identified as the suitable locations for the

reservoirs. The perseverance of the Raja of Muktyala paved way for the site

identification, design and construction of the dam.

PROJECT CONSTRUCTION

The dam water was released by the then Prime Minister's daughter,

Indira Gandhi in 1967.[5] The construction of the dam submerged an ancient

Buddhist settlement, Nagarjunakonda, which was the capital of the Ikshvaku

dynasty in the 1st and 2nd centuries, the successors of the Satavahanas in

the Eastern Deccan. Excavations here had yielded 30 Buddhist monasteries,

as well as art works and inscriptions of great historical importance. In

advance of the reservoir's flooding, monuments were dug up and relocated.

Some were moved to Nagarjuna's Hill, now an island in the middle of the

reservoir. Others were moved to the mainland.

EFFECT OF THE PROJECT

Nagarjuna Left Canal

The project benefited farmers in the districts of Guntur, Prakasam,

Krishna, Nalgonda and Khammam. The right canal (a.k.a Jawahar canal) is

203 km long and irrigates 1.113 million acres (4,500 km²) of land. The left

canal (a.k.a Lalbahadur Shastri canal) is 295 km long and irrigates 0.32

million acres (800 km²) of land in Nalgonda and Khammam districts of

Telangana region. The project transformed the economy of above districts.

52 villages were submersed in water and 24000 people were affected. The

relocation of the people was completed by 2007.[4]

POWER GENERATION

The hydroelectric plant has a power generation capacity of 815.6 MW

with 8 units (1x110 MW+7x100.8 MW). First unit was commissioned on 7

March 1978 and 8th unit on 24 December 1985. The right canal plant has a

power generation capacity of 90 MW with 3 units of 30 MW each. The left

canal plant has a power generation capacity of 60 MW with 2 units of 30 MW

each.[7]

The dam is constructed on the border of Guntur and Nalgonda districts. The

dam also provides drinking water to the Nalgonda town.

2. SRISAILAM HYDRO POWER PLANT

FACTS & FIGURES

Location Srisailam,  India

Coordinates16°05′13″N 78°53′50″E

/ 16.08694°N 78.89722°E

Construction began 1960

Opening date 1981

DAM AND SPILLWAYS

Length 512 m (1,680 ft)

Height 241 m (791 ft)

Impounds River Krishna

Reservoir

Creates Srisailam Reservoir

Catchment area 206,040 km2 (79,550 sq mi)

Surface area 800 km2 (310 sq mi)

POWER STATION CAPACITY

Turbines6 × 150MW (left bank)

7 × 110MW (right bank)

Installed capacity 1,670 MW

The Srisailam Dam is a dam constructed across the Krishna River at

Srisailam in the Kurnool district in the state of Andhra Pradesh in India and is

the 2nd largest capacity hydroelectric project in the country.

The dam was constructed in a deep gorge in the Nallamala Hills, 300 m

(980 ft) above sea level. It is 512 m (1,680 ft) long, 240.79 m (790.0 ft) high

and has 12 radial crest gates. It has a huge reservoir of 800 km2 (310 sq mi).

The left bank hydroelectric power station generates 6 × 150 MW of power

and right bank generates 7 × 110 MW of power. the dam also surrounded by

thick forests and beautiful sceneries.

The Srisailam project began in 1960, initially as a power project, across

the Krishna, near Srisailam in Andhra Pradesh. After several delays, the main

dam was finally completed twenty years later in 1981. In the meantime the

project was converted into a multipurpose facility with a generating capacity

of 770 MW by its second stage which was expected to be completed in 1987.

The dam is to provide water for an estimated 2,000 km2 (770 sq mi) with its

catchment area of 206,040 km2 (79,552 sq mi) and water spread of

1,595 km2 (616 sq mi). Under the right branch canal 790 km2 (310 sq mi) in

Kurnool and Cuddapah districts will have assured irrigation. From the initial

modest estimate of Rs.384.7 million for a power project the total cost of the

multipurpose project was estimated to cross Rs.10 billion in its enlarged

form. The 143 m (469 ft) high and 512 m (1,680 ft) wide dam has alone cost

Rs.4.04 billion together with the installation of four generating sets of 110

MW each.

The right branch canal is estimated to cost Rs.4.49 billion and the

initial investment of Rs.1.4 billion has been provided by the World Bank. The

projected cost-benefit ratio of the project has been worked out at 1:1.91 at

10% interest on capital outlay.On 2 October 2009, SriSailam dam

experienced a record inflow which threatened the dam.

Srisailam Hydel Power Project Important Dates

Project Status: Completed  Project Type/Scale: New UnitIndustry: Electricity Generation - Hydel Based Investment/Estimated Cost: Rs. 2,500.00 Crores / USD 625.00 Million Monday, September 01, 1986

Planning Commission approval received

Wednesday, May 31, 1995 Initial commissioning dateTuesday, December 31, 1996

Expenses incurred till 1 (Rs. 1,123.63 Crores)

Wednesday, February 28, 2001

Expenses incurred till 1 (Rs. 2,300.00 Crores)

Friday, April 27, 2001 First unit commissionedMonday, October 29, 2001 Second Unit CommissionedSunday, April 21, 2002 Third Unit CommissionedFriday, November 29, 2002 Fourth Unit CommissionedFriday, March 28, 2003 First unit commissionedThursday, July 31, 2003 Sixth unit completion byThursday, September 04, 2003

Sixth Unit Commissioned

Tuesday, September 30, 2003

Completed

Friday, October 31, 2003 Completion by

Future Project :- Srisailam Mini Dam

Company: Andhra Pradesh Power Generation Corpn. Ltd. Ownership: State Govt. - Commercial Enterprises Project Location: 14.5 kms down main Srisailam dam,Srisailam, Kurnool district, Andhra Pradesh, India

Project Status: Active  Project Type/Scale: New UnitIndustry: Storage & Distribution Investment/Estimated Cost: Rs. 100.00 Crores / USD 25.00 Million Thursday, January 01, 2004

Date of announcement

Saturday, July 31, 2004Initial commissioning date

ADVANTAGES AND DISADVANTAGES OF HYDROPOWER

Hydropower offers advantages over other energy sources but faces unique environmental challenges.

ADVANTAGES

Hydropower is a fueled by water, so it's a clean fuel source. Hydropower doesn't pollute the air like power plants that burn fossil fuels, such as coal or natural gas.

Hydropower is a domestic source of energy.

Hydropower relies on the water cycle, which is driven by the sun, thus it's a renewable power source.

Hydropower is generally available as needed; engineers can control the flow of water through the turbines to produce electricity on demand.

Hydropower plants provide benefits in addition to clean electricity.

Impoundment hydropower creates reservoirs that offer a variety of recreational opportunities, notably fishing, swimming, and boating. Most hydropower installations are required to provide some public access to the reservoir to allow the public to take advantage of these opportunities. Other benefits may include water supply and flood control.

DISADVANTAGES

Fish populations can be impacted if fish cannot migrate upstream past

impoundment dams to spawning grounds or if they cannot migrate

downstream to the ocean. Upstream fish passage can be aided using fish

ladders or elevators, or by trapping and hauling the fish upstream by truck.

Downstream fish passage is aided by diverting fish from turbine intakes

using screens or racks or even underwater lights and sounds, and by

maintaining a minimum spill flow past the turbine.

Hydropower can impact water quality and flow. Hydropower plants can

cause low dissolved oxygen levels in the water, a problem that is harmful to

riparian (riverbank) habitats and is addressed using various aeration

techniques, which oxygenate the water. Maintaining minimum flows of water

downstream of a hydropower installation is also critical for the survival of

riparian habitats.

Hydropower plants can be impacted by drought. When water is not

available, the hydropower plants can't produce electricity.

New hydropower facilities impact the local environment and may

compete with other uses for the land. Those alternative uses may be more

highly valued than electricity generation. Humans, flora, and fauna may lose

their natural habitat. Local cultures and historical sites may be impinged

upon. Some older hydropower facilities may have historic value, so

renovations of these facilities must also be sensitive to such preservation

concerns and to impacts on plant and animal life.